Exemplary embodiments of the present invention relate to a method and a system for automated inspection of a surface for material defects.
Material defects may have negative effects on the stability of components of structures such as bridge pillars or rotor blades of wind turbines. Material defects may propagate and lead to serious static impairments. The surfaces of such structures are therefore usually subjected to regular inspections, in particular visual inspections. In the case of surfaces that are difficult to reach and/or are at a great height (such as the blades of offshore wind turbines, for example), an inspection for material defects requires great effort because people must be lowered by cable from a great height to be able to reach the surfaces to be inspected, for example, and then to inspect them. The time required to do so is particularly important but the safety aspect is also significant.
Exemplary embodiments of the present invention are directed to a method and/or a system for inspecting surfaces for material defects, which will reduce the associated effort as well as the safety risk.
In accordance with exemplary embodiments of the present invention, a method and measurement system for inspecting a surface for material defects can be achieved using a camera configuration provided on an unmanned aircraft that is to be navigated autonomously are described below. According to one example of the invention, the method comprises the following steps: continuous measurement of a relative position of the aircraft with respect to the surface with the help of a position sensor, recording at least one image of the surface to permit an inspection (e.g., automated) of the at least one image for defects in the surface and to thereby detect and localize material defects in the surface.
In addition, a method and a measurement system for inspecting the surface of rotor blades of wind turbines for material defects by means of a camera configuration arranged on an unmanned, autonomously flying aircraft are described. According to one example of the invention, the method includes the following steps: continuous measurement of a relative position of the aircraft with respect to the surface of a rotor blade with the help of a position sensor, recording a sequence of images of the surface, with the aircraft moving along a flight path relative to the surface of the rotor blade between the individual images, so that neighboring images of the sequence represent at least partially overlapping image details of the surface of the rotor blade, assembling the images of the sequence to form an overall image of the surface of the rotor blade and automated inspection of the images of the sequence for defects in the surface to detect and localize material defects in the surface of the rotor blade.
Moreover, a measurement system suitable for performing the above mentioned methods is described.